From the Guidelines
T3 toxicosis symptoms include rapid heart rate, palpitations, anxiety, tremors, weight loss, heat intolerance, sweating, fatigue, muscle weakness, and difficulty sleeping, as confirmed by the most recent study 1. These symptoms occur due to excessive triiodothyronine (T3) in the bloodstream, accelerating the body's metabolic processes. According to the 2021 study 1, T3 toxicosis can be diagnosed through blood tests showing elevated T3 levels with normal or low TSH.
Key Symptoms
- Rapid heart rate (tachycardia)
- Palpitations
- Anxiety
- Tremors
- Weight loss despite increased appetite
- Heat intolerance
- Sweating
- Fatigue
- Muscle weakness
- Difficulty sleeping
Diagnosis and Treatment
The diagnosis is confirmed through blood tests, and treatment typically involves beta-blockers such as propranolol (40-160mg daily) to control heart rate and other sympathetic symptoms, as recommended in the 2021 study 1.
Management
The management of T3 toxicosis depends on the severity of symptoms, ranging from asymptomatic or mild symptoms (Grade 1) to severe symptoms (Grade 3-4), as outlined in the 2021 study 1.
- Grade 1: Can continue ICPi, beta-blocker for symptomatic relief, and close monitoring of thyroid function.
- Grade 2: Consider holding ICPi, beta-blocker for symptomatic relief, hydration, and supportive care.
- Grade 3-4: Hold ICPi, endocrine consultation, beta-blocker, hydration, and supportive care, and consider hospitalization in severe cases.
From the Research
Symptoms of Triiodothyronine (T3) Toxicosis
The symptoms of T3 toxicosis, also known as thyrotoxicosis, include:
- Nervousness 2
- Heat intolerance 2, 3, 4, 5, 6
- Weight loss 2, 3, 4, 5, 6
- Fatigue 2
- Palpitations 3, 4, 6
- Tremors 3
- Agitation 3
- Anxiety 4
- Insomnia 4
- Diarrhea 4
- Unintentional weight loss 4
- Weakness 6
- Sore throat 6 (in patients with thyroiditis)
- Sinus tachycardia 6
- Atrial fibrillation 6
Common Symptoms in Hospitalized Patients
In hospitalized patients with newly diagnosed thyrotoxicosis, the most common symptoms are:
Thyrotoxicosis Syndromes
Thyrotoxicosis is not one but many syndromes, and a variety of thyroid and nonthyroid disorders can clinically simulate thyrotoxicosis 5.